Field of the Disclosure
Embodiments of the present invention relate to a display device, and more particularly, to an organic light emitting diode (OLED) display device and a method of driving the same.
Discussion of the Related Art
With the advancement of an information-oriented society, various requirements for the display field are increasing, and thus, research is being conducted on various flat panel display devices that are thin, light, and have low power consumption. For example, the flat panel display devices are often categorized into liquid crystal display (LCD) devices, plasma display panel (PDP) devices, OLED display devices, etc.
Particularly, some of the OLED display devices that are being actively studied apply data voltage (Vdata) having various levels to respective pixels in order to display different grayscale levels, thereby realizing an image.
To this end, each of a plurality of pixels may include one or more capacitors, an OLED, and a driving transistor that are current control elements. Particularly, a current flowing in the OLED may be controlled by the driving transistor, and the threshold voltage deviation of the driving transistor and the amount of current flowing in the OLED may be changed by various parameters, causing non-uniformity in screen luminance.
However, a threshold voltage deviation of the driving transistor can occur because the characteristic of the driving transistor changes due to a variable manufacturing process used for the driving transistor. To overcome this limitation, each pixel may generally include a compensation circuit that includes a plurality of transistors and capacitors for compensating for the deviation of the threshold voltage.
Recently, as consumers' requirements for high definition has increased, a high-resolution OLED display device has been demanded. To this end, it is generally necessary to integrate more pixels into a unit area for higher resolution, and thus, it is typically required to reduce the numbers of transistors, capacitors, and lines included in the compensation circuit that compensates for the deviation of a threshold voltage.
Moreover, image quality is usually degraded because the amount of current flowing in the OLED is not uniform due to various parameters, and thus, it is typically necessary to compensate for the change in the amount of current due to a parameter such as source voltage.